Change Carburator "Rochester VS Edelbrock" on C3 1975 SB

[GiuG]

Hi guys,
I decide to change it, my choice is a Edelbrock 1906 AVS2 650 cfm. They say that is simple to set and with the jets and springs easy to customized without open it... But I know no one, who already have it. Any clue or suggestion on this carb version?
I`m not a mechanic so I need something that I can manage myself. Because I spent too much time and money to make a Rochester Q-jet works for me without luck, also is badly liking fuel from the fast idle cane.

 

[Roscobbc]

You need to make sure that any replacement carb will fit the Rochester Quadrajet 'spread-bore' specific inlet manifold. So called because the primary 'holes' are much smaller than the secondaries. Any alternative carb like a Holley or Edlbrock will need to also be of the 'spread-bore' pattern.............if primaries and secondaries are same size you will need to get a new inlet manifold to suit..........

 

[GiuG]

Something like these 2 should be fine?

 

[Roscobbc]

Fitting a spreadbore adaptors could be a potential issue.........the thickness of the adaptor could create issues with hood clearance on some Vettes. Not a very efficient method of using a Holley (or Edelbrock) carb.

 

[Forrest Gump]

You could get a thinner height air filter element if the added height of the adapter causes the hood to clash. Less airflow but doubt you notice any performance loss for normal driving.

 

[Chuffer]

Make sure you get a drop base air cleaner too as this will give more clearance under the hood.

 

[GiuG]

Make sure you get a drop base air cleaner too as this will give more clearance under the hood.

Not Bad Idea indeed, also at the moment the Filter's stud is quite long, if it will be a problem maybe I can cut it a bit also I found this adaptor, personally I prefer the chunky one, of course these solutions are not optimal, a brand-new inlet manifold will be awesome, but this alternative is way more cheap if it's hold well the air_flow of course!!!!

 

[Roscobbc]

GM's own 'drop base' as used on late 60's/early 70's big block Vette's is as low as you can get and sa good as you'll get ...........perhaps someone else hopefully more knowledgeable can tell us all whether this drop base filter base is used on ALL big block and small block engines with Quadrajet carbs and perhaps Holleys.

 

[Roscobbc]

Thought about buying a 'remanufactured' Quadrajet?......not exactly cheap (expecially with $/£ conversion and shipping) but if selected correctly an easy 'plug 'n' play' option. https://www.mamotorworks.com/corvet...77-quadrajet-remanufactured-carburetor-603774

 

[antijam]

When I bought my small block it had a lot of problems with popping and banging on the overrun and bogging when accelerating. The carb was a Quadrajet but not the correct one for the car. After many hours of fruitless fiddling I bit the bullet and bought a restored and rebuilt Quadrajet correctly numbered and dated for the car from this vendor.

It was very expensive but after some rejetting to take account of the headers in place of standard manifolds it performs faultlessly. Progressive delivery and instant response to foot down on the loud pedal.

 

[GiuG]

When I bought my small block it had a lot of problems with popping and banging on the overrun and bogging when accelerating. The carb was a Quadrajet but not the correct one for the car. After many hours of fruitless fiddling I bit the bullet and bought a restored and rebuilt Quadrajet correctly numbered and dated for the car from this vendor.

It was very expensive but after some rejetting to take account of the headers in place of standard manifolds it performs faultlessly. Progressive delivery and instant response to foot down on the loud pedal.

I'm Done with the Q-jet, mine It has been reformed twice, and now is bleeding fuel from the fast idle cane, not safe. Reform a q-jet, as you said is not cheap, so I'll try a brand new one. Fingers cross it will resolve the problem... maybe or open a cascade issues